Hi, just set up a new tank two weeks ago, waited a week bought 3 rosy barbs and an algea eater. Everything was fine until yesterday, 1 of my rosy barbs which used to be active now just sits at the top of the tank looking up. Won't eat, doesn't spend much time swimming at all. The other two barbs are swimming around as normal, and the algea eater has no interactions with any of the fish. I've tested the water everything is normal, ammonia, nitrogen, Ph, etc. No signs of ich or parasites that I can tell on the fish, also, this fish I've had a hard time telling what gender it is, some days it has been reddish, some, like today is golden. Any help would be appreciated.